There is a demand in the marketplace for improved methods of sealing perishable consumer products to maintain their freshness. Historically, perishable products such as baked goods and vegetables had to be brought to market and sold quickly before exposure to the atmosphere caused the products to lose their freshness. The advent of plastics resulted in many products being wrapped or packaged in plastic, both in the form of flexible plastic bags and solid plastic containers. The use of plastics has greatly improved the "shelf life" of perishable products, allowing both merchants and their customers to store the products for longer periods of time, resulting in a substantial savings.
A number of sealable containers are currently available and are typically formed from plastic or other lightweight material. For example, U.S. Pat. No. 4,753,351 to Guillin discloses a P.V.C. or polystyrene sealable container that includes a base tray and a hinged cover. The food is placed in the tray and the cover is brought into sealed engagement with the base tray to seal the food from the environment. Similarly, U.S. Pat. No. 4,976,370 to Cassel discloses a container and sealing lid formed of plastic such as polypropylene or polyethylene.
While such containers have successfully increased the life of perishable products, the effectiveness of the container is limited by the ability of the latch between the base of the container and the lid to prevent air from entering the container.
Containers are also used to store goods without isolating or sealing the goods from the environment. For example, certain baked goods are placed in containers for transportation or sale before the goods have cooled. The containers that hold these hot goods are vented to allow air to escape from the container while the goods cool to room temperature to prevent moisture buildup in the container. Such containers, while not sealed from the environment, nevertheless require that a secure latch be used to prevent the lid from inadvertently opening and spilling the goods stored therein.